Hexamethylenetetramine: 1,3,5,7-Tetraazatricyclo decane

Although several workers have studied the reaction of hexamethylenetetramine (hmt l,3,5,7-tetraazatricyclo[3.3.1.13.7]decane) with phosgene, the product has never been fully characterized, despite its alleged importance as a prophylactic agent in phosgene poisoning (Section 2.6). 

Tetraazatricyclo [3,3,1,1] decane. See Hexamethylenetetramine Tetrabasic lead fumarate. See Lead fumarate tetrabasic... 

Tertiary amines [70], some inorganic salts [71], ammonia [70], and l,3,5,7-tetraazatricyclo[3.3.3.P ]decane (hexamethylenetetramine) [72] can catalyze the formation of resoles. The basic pH in the reaction mixture produees a phenolate anion. This anion possesses a higher electron density at the ortho and para positions. Therefore, the electrophilic attack of the carbon end of the methanal occurs more efficiently in these positions. Furthermore, the dehydration of the hydroxymethylol group oecurs slower because the cation of the basic catalyst stabilizes the hydroxymethylated phenols. A typical example for such a stabilized structure is given in Seheme 3. 

Novolacs can be transformed into insoluble, nomnelting, thermally stable fheimosets by crosslinking reaction with 1,3,5,7-tetraazatricyclo-[3.3.3. H ]-decane (hexamethylenetetramine), oxiiane (epoxides), diisocyanates, urea. 

Before leaving the topic of oxidation of alkyl halides, it is worthwhile noting that benzylic (C6H5CH2X X = Cl, Br, I) and allylic (RCH=CH-CH2X X = Cl, Br, I) halides and related compounds that form stabilized carbocations, have long been known to undergo oxidation by heating them with hexamethylenetetramine (l,2,5,8-tetraazatricyclo[3.3.1.1 ]decane) in water. ... 

The details of the process shown in this footnote are not known. However, it is possible that partial hydrolysis of the adamantane (tricyclo[3.3.1.E ]decane, Chapter 1) analogue hexamethylenetetramine (l,2,5,8-tetraazatricyclo[3.3.1.1 - ]decane) to formaldehyde (methanal, CH2O) and ammonia (NH3), from which it was formed by a condensation reaetion (see Chapter 10), provides an oxidizing agent (methanal). 

However, it is worth returning to the chemistry of hexamethylenetetramine (1,3,5,7-tetraazaadamantane or l,3,5,7-tetraazatricyclo[3.3.1.H ]decane, C6H12N4, Chapter 9 and Table 10.2) that is formed by the condensation of ammonia (NH3) with methanal (formaldehyde, H2OO). As was noted as early as 1895 by M. Delepine, in a reaction now bearing his name, alkyl halides react with hexamethylenetetramine to produce A-substituted derivatives of the hexamethylenetetramine, which can then be hydrolyzed to aldehyde, ammonia, and substituted amine. Not unexpectedly, it has become clear that benzyhc and allylic halides react best (Scheme 10.30). 

Scheme 10.30. An example of the use of hexamethylenetetramine 1,3,5,7-tetraazaadamantane or l,3,5,7-tetraazatricyclo[3.3.1.1 ]decane), followed by hydrolysis to effect replacement of a halogen by nitrogen (the Delepine reaction, see Delepine, M. C. R. Seances Acad. 5 ci., 1895, 120,501).

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